"In the 12.10 release, Canonical entered into an affiliate agreement
with Amazon. Under the agreement, search results from Amazon appear
when users search their local hard drive. In the upcoming 13.04
release, this feature is going to be greatly expanded, with results
from dozens of other companies appearing unless users turn the feature
It goes on to say:
"many distributions have compromised their anti-proprietary positions
in order to get working hardware drivers and audio codecs."
I believe this is true for Ubuntu. This brings me to several questions:
Is Amazon still an affiliate of Canonical?
Is Elementary OS affiliated with any 3rd-parties that privacy-conscious users may want to opt-out of?
Are their any proprietary components used in Elementary OS by default?
As far as I know there is still an "Amazon App" pre-installed by default on current Ubuntu versions. However it is really just a link to the website and can be easily uninstalled. What you're referring to in your first quote is the Shopping Lens. It could also be easily uninstalled and in later versions of Ubuntu there was a setting to disable it, IIRC. However with 17.10 Canonical killed Unity and with it its lenses. Current Ubuntu uses Gnome Shell and there is no respective piece of software that does something similar. In Gnome Shell there is a similar concept called Search Providers, but there is no "Shopping Search Provider". It seems Canonical learned the lesson from the uproar that followed the introduction of the shopping lens.
elementary OS seems to be very concerned about the privacy of their users and doesn't come with anything like that pre-installed. elementary OS has an indexing service, but the collected data is only used for things like search and does not leave your computer / account. This can be disabled alltogether or on a filetype basis. See screenshot below.
elementary OS may come with some proprietary firmware files that are needed for some peripheral devices (like printers) to work at all. This is done by most Linux distributions nowadays. Other than that the OS itself should not contain any non-free software.